Process for patinating wood and other vegetable materials



Patented Aug. 1, 1939 UNITED STATES PATENT OFFIQE Eugene Plantrou, Rouen, France No Drawing. Application January 31, 1939, Se-

rial No. 253,942. 1938 1 Claim.

It is known that old wood and furniture have a particular patina, due to the slow action of the atmospheric agents, which is characterized by very warm tones, that is to say tones in which the yellow and orange shades dominate, and which contributes to increase their artistic and marketable values.

Attempts have been made to produce artificially on wood and furniture, this colouring which is particular to old furniture but the processes used for this purpose involve drawbacks owing to the fact that they do not enable the desired tones to be obtained with all their warmth, that the colourings they impart to the wood and furniture become attenuated and alter fairly quickly, and that finally these treating processes are long and expensive.

The invention aims at overcoming these drawbacks and, for this purpose, it has for its object a process for treating Wood, or the component elements of wooden furniture, or again wooden furniture which is finished (but not yet varnished, encausticated, or waxed), or again for treating rattan or reed and straw intended to form or forming cane or wickerwork seats or other furniture, or again for treating straw, rush, reed, etc, fabric or matting and other products or articles of ligneous and more generally vegetable nature, said process consisting, in principle, in subjecting them, in order to impart to same a similar colouring to that of the same articles when old, to the action of one or a plurality of oxygenated compounds of nitrogen, preferably in the nascent state and, in particular, to the action of the mixture called rutilant vapors.

This dry treating process enables the warm, durable and unalterable tones which reproduce those of the patina due to time, to be obtained quickly and inexpensively.

An example, which is given. simply in an indicative and in nowise limitative manner, will enable the process which forms the object of the invention to be thoroughly understood.

The wood, element of wooden furniture, or wooden furniture, or other products or articles of In Luxemburg, February 1'7,

vegetable nature, are enclosed in a fluid-tight bin inside which (or are introduced into an open tank at the bottom of which) is produced an evolution of rutilant vapours, for example by the action of hydrochloric acid HCl on sodium nitrite NaNO: the rutilant vapours evolved are in this case composed of a mixture of nitric oxide N0, of nitrous anhydride N203, of nitrogen peroxide N02 and of nitrosyl chloride NOCl. After a very short time, for example two minutes, the gases are evacuated, either into the atmosphere, or into another treating bin where they are used again.

The degree of concentration of the treating gases and their time of action are factors which may be varied for modifying the intensity of their action, but an action which is carried too far neither affects nor damages the wood or furniture which in this case assumes the maximum antique colouring: in this case a current of air may be used for removing the excess of gas which may have penetrated into the pcres of the wood or furniture,

Instead of operating in a closed bin, or in an open tank, it is also possible to treat the wood and furniture by means of jets of rutilant vapours but it is obvious that the operator will have to be protected.

It is of course understood that, without exceeding the scope of the invention, modifications and improvements of detail may be imagined. For example, the previous action of a vacuum or that of an over-pressure may be used to obtain a deeper penetration.

I claim:

A process for imparting, by means of a dry treatment, to wood, wooden furniture, straw, rattan, rushes and other products of vegetable nature, a similar colouring to that due to time, said process consisting, in principle, in subjecting said products or articles to the action of one or a plurality of oxygenated compounds of nitrogen, preferably in the nascent state and, in particular, to the action of the mixture called rutilant vapours.

EUGENE PLANTROU. 

